TY - JOUR
T1 - The origin of the odorant receptor gene family in insects
AU - Brand, Philipp
AU - Robertson, Hugh M.
AU - Lin, Wei
AU - Pothula, Ratnasri
AU - Klingeman, William E.
AU - Jurat-Fuentes, Juan Luis
AU - Johnson, Brian R.
N1 - We thank Leslie Vosshall, Roman Arguello, and one anonymous reviewer for helpful comments that improved the manuscript. We thank Stephen Richards for permission to examine unpublished genome sequences from the i5k pilot project, and Kimberly Walden for assistance with BLAST searches. This work was funded by a National Science Foundation grant, IOS-1456678, to Brian Johnson and Juan Luis Jurat-Fuentes, and a USDA Hatch grant to Brian Johnson (CA-D-ENM 2161-H).
PY - 2018/7/31
Y1 - 2018/7/31
N2 - The origin of the insect odorant receptor (OR) gene family has been hypothesized to have coincided with the evolution of terrestriality in insects. Missbach et al. (2014) suggested that ORs instead evolved with an ancestral OR co-receptor (Orco) after the origin of terrestriality and the OR/Orco system is an adaptation to winged flight in insects. We investigated genomes of the Collembola, Diplura, Archaeognatha, Zygentoma, Odonata, and Ephemeroptera, and find ORs present in all insect genomes but absent from lineages predating the evolution of insects. Orco is absent only in the ancestrally wingless insect lineage Archaeognatha. Our new genome sequence of the zygentoman firebrat Thermobia domestica reveals a full OR/Orco system. We conclude that ORs evolved before winged flight, perhaps as an adaptation to terrestriality, representing a key evolutionary novelty in the ancestor of all insects, and hence a molecular synapomorphy for the Class Insecta.
AB - The origin of the insect odorant receptor (OR) gene family has been hypothesized to have coincided with the evolution of terrestriality in insects. Missbach et al. (2014) suggested that ORs instead evolved with an ancestral OR co-receptor (Orco) after the origin of terrestriality and the OR/Orco system is an adaptation to winged flight in insects. We investigated genomes of the Collembola, Diplura, Archaeognatha, Zygentoma, Odonata, and Ephemeroptera, and find ORs present in all insect genomes but absent from lineages predating the evolution of insects. Orco is absent only in the ancestrally wingless insect lineage Archaeognatha. Our new genome sequence of the zygentoman firebrat Thermobia domestica reveals a full OR/Orco system. We conclude that ORs evolved before winged flight, perhaps as an adaptation to terrestriality, representing a key evolutionary novelty in the ancestor of all insects, and hence a molecular synapomorphy for the Class Insecta.
UR - https://www.scopus.com/pages/publications/85052105221
UR - https://www.scopus.com/pages/publications/85052105221#tab=citedBy
U2 - 10.7554/eLife.38340
DO - 10.7554/eLife.38340
M3 - Article
C2 - 30063003
AN - SCOPUS:85052105221
SN - 2050-084X
VL - 7
JO - eLife
JF - eLife
M1 - e38340
ER -